To a solution of tert-butyl(5-amino-4-chloro-2-fluorophenyl)carbamate (5.17 g, 19.8 mmol) in tetrahydrofuran (10 mL) were added N-ethyl-N-isopropylpropane-2-amine (6.93 mL, 39.6 mmol) and 2-chloro-5-nitropyrimidin-4-yl thiocyanate (6.44 g, 29.7 mmol), and the mixture was stirred at room temperature for 1 hr. To the reaction mixture was added water (200 mL), and the mixture was extracted with ethyl acetate (300 mL, 50 mL). The combined organic layer was washed with saturated brine (30 mL), and dried over anhydrous sodium sulfate. The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure to give tert-butyl {4-chloro-2-fluoro-5-[(5-nitro-4-thiocyanatopyrimidin-2-yl)amino]phenyl}carbamate as a yellow amorphous solid. The obtained compound was used for the next reaction without further purification.
